Israeli officials declined to confirm the focus of his visit, but it comes amid signs of heightened Israeli concern about Syria.

“Hezbollah has set up several bases in Syria, near known locations where Syrian President Bashar Assad is holding parts of his chemical warfare arsenal,” Ynet’s Ron Ben-Yishai reported Monday.

Netanyahu “recently held a number of security assessments focusing on the developments in the war-torn country,” the Ynet report said. “Israel’s defense establishment has been holding similar assessments, focused on the potential shift in the balance of power between the IDF and Hezbollah, in the event that the latter would get hold of Assad’s WMDs.”

Netanyahu spoke by phone with President Obama on Monday, following a meeting Sunday with US Ambassador to Israel Dan Shapiro.

Netanyahu also dispatched his National Security Advisor Yaakov Amidror to Moscow, reportedly to seek Russian help in averting various Syrian contingencies.